As the scale of the electrical system becomes more and more large and the structure becomes more and more complex, the performance of the electrical automation device is therefore required to be higher. This paper studies the electrical system automation device, and from the perspective of universality, designs and establishes the hardware platform of the electrical system automation device composed of six plug-ins, such as human-machine interface, auxiliary switch input, AC input, communication, power supply, and central processor. On this basis, μC/OS-II is adopted as the embedded real-time operating system of this paper to develop and design the software of the electrical system automation device. Then, the principle of the protection device for embedded system electrical automation is analyzed, and a microcomputer line protection device based on the full-circle Fuchs algorithm is proposed. The empirical analysis of the embedded system electrical automation device shows that the maximum system task response time is 145 μs and the minimum is 10 μs, which are all no more than 1 ms. When testing including the single board state, the keyboard, the alphabetical mode, the basic function, and the single board line module sending and receiving, the pass rate of all the testing items is more than 99%, which verifies that this paper is based on the embedded real-time operating system of the feasibility and effectiveness of the electrical automation device.